Certain types of industrial ovens, such as tray ovens or tunnel ovens, employ oven drive units including endless conveyors or roller chains that carry goods through the interior of the oven. In such ovens, the oven drive unit and other parts of the oven are susceptible to damage caused by jam-ups due to failure of mechanical components, interference between moving parts and misfeeding of goods, for example. When such problems occur, it is critical that they are detected quickly so that the oven drive unit can be shut down, paused or slowed down in order to prevent or minimize damage to the oven.